LWN.net Logo

Lots of partitions? what for?

Lots of partitions? what for?

Posted Jul 17, 2008 9:36 UTC (Thu) by smurf (subscriber, #17840)
Parent article: Block layer: integrity checking and lots of partitions

There's LVM. it does exactly the same thing a partition does, only better (you can resize
arbitrary partitions, or even move them to another disk transparently).

Thus I kindof doubt that this is much of a problem.


(Log in to post comments)

Lots of partitions? what for?

Posted Jul 17, 2008 10:54 UTC (Thu) by ljt (guest, #33337) [Link]

I use LVM on top of RAID5, but it is _very_ convenient to be able to slice the enormous disks
in many parts. 
I sliced my 4 disks in 14 partitions each, making thus 14 RAID5 volumes. I can now assign
those PVs to whatever VGs I am using. It is extremely flexible.

the *only* problem I encounter is that 14 partitions is not enough: 400Go/14partitions*(4-1
RAID disks)=85 Go. I would rather have had a 20Go unit.

Lots of partitions? what for?

Posted Jul 18, 2008 7:56 UTC (Fri) by dgm (subscriber, #49227) [Link]

Just to ensure I parsed it right:

Go = Gigaoctet = French abbreviation = GB (Gigabyte) ?

Go explained

Posted Jul 18, 2008 20:57 UTC (Fri) by pr1268 (subscriber, #24648) [Link]

My recently-purchased SATA disk says "1 TB/To" and "32 MB Cache/Mo Cachette" on the retail box, so my assumption is yes, this is French. Plus, the line Guarantie limitée de 5 ans would seem to confirm this.

I don't know French, but I can recognize it in written/printed text. Yes, this is a late-model Seagate consumer drive. :-)

Go explained

Posted Jul 18, 2008 21:14 UTC (Fri) by nix (subscriber, #2304) [Link]

It's French: 'octet'. (You often see this in older standards documents, 
too, which have to be clear about the number of bits in a byte.)

Lots of partitions? what for?

Posted Jul 18, 2008 9:14 UTC (Fri) by smurf (subscriber, #17840) [Link]

Well, personally I don't see any reason for having multiple flexible-sized VGs on a single
RAID in the first place, much less ~60 of them, but maybe I'm just missing something.

Lots of partitions? what for?

Posted Jul 18, 2008 22:08 UTC (Fri) by giraffedata (subscriber, #1954) [Link]

The point is you can do that with LVM instead of partitions. Slice each disk (which is a PV and VG) into 14 LVs, make 14 RAID5 volumes out of those, assign those PVs to VGs, ...

I've always hated partitions; even before LVM existed I knew a stacked device driver was a cleaner way than having partitioning intelligence in the lowest level of kernel disk management code and a weird minor number interpretation scheme.

Originally (pre-Linux), partitions were actually in a layer beneath the kernel and that made sense for the problems that had to be solved at that time. But inside Linux, LVM (or anything else layered on top of the physical device) is the cleaner way to go.

Lots of partitions? what for?

Posted Jul 24, 2008 9:01 UTC (Thu) by eduperez (guest, #11232) [Link]

> I use LVM on top of RAID5, but it is _very_ convenient to be able to slice the enormous
disks in many parts.
> I sliced my 4 disks in 14 partitions each, making thus 14 RAID5 volumes. I can now assign
those PVs to whatever VGs I am using. It is extremely flexible

Could you explain why do you need to do that, please?

Lots of partitions? what for?

Posted Jul 24, 2008 13:07 UTC (Thu) by yhdezalvarez (guest, #29255) [Link]

Does LVM supports write barriers already? Last time I checked it didn't. So I'm using
partitions for now.

Lots of partitions? what for?

Posted Oct 16, 2008 5:29 UTC (Thu) by cortana (subscriber, #24596) [Link]

I believe it does for 'linear' mappings. But that's just my recollection from a recent LWN article on the topic, so I may be wrong.

Copyright © 2013, Eklektix, Inc.
Comments and public postings are copyrighted by their creators.
Linux is a registered trademark of Linus Torvalds